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IP Online First, published on May 13, 2014 as 10.1136/injuryprev-2014-041199 Original article
Incidence trends of injury among the elderly in Spain, 2000–2010 Eva Cirera,1,2 Katherine Pérez,3,4,5 Elena Santamariña-Rubio,3,4,5 Ana M Novoa,3,5 Marta Olabarria3,4,5 1
Departament de Salut i Acció Social, Universitat de Vic (UVic), Vic, Barcelona, Spain 2 Universitat Pompeu Fabra (UPF), Barcelona, Spain 3 Agència de Salut Pública de Barcelona (ASPB), Barcelona, Spain 4 CIBER Epidemiologia y Salud Pública (CIBERESP), Barcelona, Spain 5 Institut d’Investigació Biomèdica (IIB Sant Pau), Barcelona, Spain Correspondence to Eva Cirera, Departament de Salut i Acció Social, Universitat de Vic, c/Sagrada Familia, 7, Vic, Barcelona 08500 Spain; [email protected] Received 7 February 2014 Revised 3 April 2014 Accepted 16 April 2014
ABSTRACT Background The significant growth in the elderly population expected in the coming years demands a thorough and up-to-date understanding of the incidence of injuries in this group for purposes of prevention polices and their evaluation. The aim of this study was to describe the incidence of injuries in hospital inpatients over 64 years of age in Spain, stratified by sex, age group, and the severity and mechanism of injury, and to analyse trends in incidence during the period 2000–2010. Methods Descriptive trends study using data from the National Hospital Discharge Register. The dependent variable was the number of hospital discharges with injury. Stratified incidence rates were calculated per 100 000 inhabitants. Trends, in terms of annual per cent change, were assessed using Poisson regression with discharge year as the independent variable. Results Rates of injury were higher among women than men, increased with age in both sexes, with individuals aged ≥85 years having a fivefold greater risk than those aged 65–69 years. During the period 2000–2010, incidence increased annually by 1.1% in men and 0.9% in women aged 75–79 years, 2.3% and 1.6% in 80–84-year-olds and 3.3% and 2.4% in ≥85-year-olds, respectively. The incidence of all levels of injury severity and all mechanisms of injury increased during the study period, except for traffic injuries, which decreased. Conclusions Incidence of injury in the elderly is rising, particularly in older individuals, indicating that the increase in the number of hospitalisations is not a consequence of population aging only.
INTRODUCTION
To cite: Cirera E, Pérez K, Santamariña-Rubio E, et al. Inj Prev Published Online First: [ please include Day Month Year] doi:10.1136/ injuryprev-2014-041199
The continuing increase in life expectancy in developed countries, together with the decline in birth rate, means that the elderly have become a rapidly expanding age segment of the population. Individuals over 64 years of age accounted for ∼15% of the European population (100 million people) at the beginning of this century, and this group is projected to account for almost 22% by 2030 (165 million).1 Injuries suffered by individuals in this age group tend to be more severe and to have a worse outcome than those of a similar mechanism suffered by younger individuals.2 3 Mechanisms of injury with a relatively low energy transmission, such as same level falls, that are unlikely to cause injuries in young people, can cause substantial injuries in elderly individuals.4 Moreover, greater comorbidity in older individuals3 results in poorer outcomes compared with young adults with the
Cirera E, et al. Inj Prev 2014;0:1–7. doi:10.1136/injuryprev-2014-041199 Copyright Article author (or their employer) 2014.
same severity or mechanism of injury,5 higher mortality and complication rates,6 7 greater length of hospitalisation and use of intensive care services,8 and lower probability of returning to the preinjury status.5 9 European hospitals attend to ∼6.7 million individuals aged ≥60 years with injuries annually, accounting for 59/1000 people from this age group. One in three of these individuals treated in the emergency department (ED) shall be admitted to the hospital.9 The incidence of injuries increases with age, and rates in individuals over 84 years old can be five to six times those in people aged 65–74 years, depending on sex, mechanism of injury or attendance service (ED or hospitalisation).10–12 In addition, the incidence among women, who are more numerous in this age group, is higher than that among men in all age groups.8 13 These results indicate that injuries among the elderly are a major public health problem, in terms of the number and characteristics of the individuals affected, and the resources needed for treatment and prevention.14 Previous studies have shown an increasing trend in the incidence of injury in the elderly.13 15 In USA between 2001 and 2007 mortality and morbidity from injury in over 64-year-olds rose by 6% and 7%, respectively, reaching an incidence of 8100/100 000 in the last year of study.15 However, most studies have reported only partial data. Some have accounted only for fall-related injuries treated in hospital, which were generally found to be increasing in frequency, for example, in the USA (2001–2008)10 and Netherlands (1995–2008),16 although this trend was reversed in a Finnish study, in which the incidence of injury declined from the late 1990s in individuals over 79 years.17 In Spain in 2009, 7% of men and 15% of women aged ≥65 years had suffered an injury in the previous year.18 According to hospital data on injuries, this group represents 20% of ED-treated individuals,19 16% of admitted patients and 33% of deaths.20 The most common mechanisms were falls and pedestrians involved in traffic crash collisions.20 Other studies, focused on specific injuries and their trends, have shown a significant increase in the incidence of traumatic brain injury,21 and stabilisation of the incidence of hip fracture.22 The aim of this study was to describe the incidence of injuries in hospital inpatients aged >64 years in Spain according to sex, age, and the severity and mechanism of injury, and to analyse trends in incidence during the period 2000–2010 using data from the National Hospital Discharge Register (HDR).
Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://injuryprevention.bmj.com/ on November 9, 2014 - Published by group.bmj.com
Original article METHODS Design and population We performed a descriptive trends study of the population over 64 years of age resident in Spain during the period 2000–2010.
Sources of information We used data from two sources, the National HDR of the Spanish Health Information Institute (Ministerio de Sanidad, Servicios Sociales e Igualdad), which provides information on hospital discharges for injuries and data from the National Statistics Institute, which provides information on the resident population. The HDR includes information from the public hospitals network and some private hospitals, and has population coverage of over 95%. This population coverage has been steady during all the study period.
Study variables and inclusion criteria The dependent variable was the number of hospital discharges with a primary diagnosis of injury. We define injury as traumatic injury23: codes 800–904, 910–957 and 959 International Classification of Diseases Clinical Modification, Review 9. As a way of approximating the selection of new disease cases (incidence) we also excluded programmed admissions and readmissions (the HDR considers as readmission any new application for admission to the same hospital within 30 days of the patient’s prior discharge). Non-Spanish residents were excluded in order to compute national incidence rates. The independent variable was discharge year, and the stratification variables were age (in five groups: 65–69 years, 70–74 years, 75–79 years, 80–84 years or ≥85 years), sex, injury severity and injury mechanism. Injury severity was determined using the New ISS (NISS)24 computed as the sum of the three AIS most severe regardless of the region of the body in which they occur. The NISS was derived using the ICD Programs for Injury Categorization (ICDPIC) option for STATA,25 and was classified as slight or moderate (NISS
IP Online First, published on May 13, 2014 as 10.1136/injuryprev-2014-041199 Original article
Incidence trends of injury among the elderly in Spain, 2000–2010 Eva Cirera,1,2 Katherine Pérez,3,4,5 Elena Santamariña-Rubio,3,4,5 Ana M Novoa,3,5 Marta Olabarria3,4,5 1
Departament de Salut i Acció Social, Universitat de Vic (UVic), Vic, Barcelona, Spain 2 Universitat Pompeu Fabra (UPF), Barcelona, Spain 3 Agència de Salut Pública de Barcelona (ASPB), Barcelona, Spain 4 CIBER Epidemiologia y Salud Pública (CIBERESP), Barcelona, Spain 5 Institut d’Investigació Biomèdica (IIB Sant Pau), Barcelona, Spain Correspondence to Eva Cirera, Departament de Salut i Acció Social, Universitat de Vic, c/Sagrada Familia, 7, Vic, Barcelona 08500 Spain; [email protected] Received 7 February 2014 Revised 3 April 2014 Accepted 16 April 2014
ABSTRACT Background The significant growth in the elderly population expected in the coming years demands a thorough and up-to-date understanding of the incidence of injuries in this group for purposes of prevention polices and their evaluation. The aim of this study was to describe the incidence of injuries in hospital inpatients over 64 years of age in Spain, stratified by sex, age group, and the severity and mechanism of injury, and to analyse trends in incidence during the period 2000–2010. Methods Descriptive trends study using data from the National Hospital Discharge Register. The dependent variable was the number of hospital discharges with injury. Stratified incidence rates were calculated per 100 000 inhabitants. Trends, in terms of annual per cent change, were assessed using Poisson regression with discharge year as the independent variable. Results Rates of injury were higher among women than men, increased with age in both sexes, with individuals aged ≥85 years having a fivefold greater risk than those aged 65–69 years. During the period 2000–2010, incidence increased annually by 1.1% in men and 0.9% in women aged 75–79 years, 2.3% and 1.6% in 80–84-year-olds and 3.3% and 2.4% in ≥85-year-olds, respectively. The incidence of all levels of injury severity and all mechanisms of injury increased during the study period, except for traffic injuries, which decreased. Conclusions Incidence of injury in the elderly is rising, particularly in older individuals, indicating that the increase in the number of hospitalisations is not a consequence of population aging only.
INTRODUCTION
To cite: Cirera E, Pérez K, Santamariña-Rubio E, et al. Inj Prev Published Online First: [ please include Day Month Year] doi:10.1136/ injuryprev-2014-041199
The continuing increase in life expectancy in developed countries, together with the decline in birth rate, means that the elderly have become a rapidly expanding age segment of the population. Individuals over 64 years of age accounted for ∼15% of the European population (100 million people) at the beginning of this century, and this group is projected to account for almost 22% by 2030 (165 million).1 Injuries suffered by individuals in this age group tend to be more severe and to have a worse outcome than those of a similar mechanism suffered by younger individuals.2 3 Mechanisms of injury with a relatively low energy transmission, such as same level falls, that are unlikely to cause injuries in young people, can cause substantial injuries in elderly individuals.4 Moreover, greater comorbidity in older individuals3 results in poorer outcomes compared with young adults with the
Cirera E, et al. Inj Prev 2014;0:1–7. doi:10.1136/injuryprev-2014-041199 Copyright Article author (or their employer) 2014.
same severity or mechanism of injury,5 higher mortality and complication rates,6 7 greater length of hospitalisation and use of intensive care services,8 and lower probability of returning to the preinjury status.5 9 European hospitals attend to ∼6.7 million individuals aged ≥60 years with injuries annually, accounting for 59/1000 people from this age group. One in three of these individuals treated in the emergency department (ED) shall be admitted to the hospital.9 The incidence of injuries increases with age, and rates in individuals over 84 years old can be five to six times those in people aged 65–74 years, depending on sex, mechanism of injury or attendance service (ED or hospitalisation).10–12 In addition, the incidence among women, who are more numerous in this age group, is higher than that among men in all age groups.8 13 These results indicate that injuries among the elderly are a major public health problem, in terms of the number and characteristics of the individuals affected, and the resources needed for treatment and prevention.14 Previous studies have shown an increasing trend in the incidence of injury in the elderly.13 15 In USA between 2001 and 2007 mortality and morbidity from injury in over 64-year-olds rose by 6% and 7%, respectively, reaching an incidence of 8100/100 000 in the last year of study.15 However, most studies have reported only partial data. Some have accounted only for fall-related injuries treated in hospital, which were generally found to be increasing in frequency, for example, in the USA (2001–2008)10 and Netherlands (1995–2008),16 although this trend was reversed in a Finnish study, in which the incidence of injury declined from the late 1990s in individuals over 79 years.17 In Spain in 2009, 7% of men and 15% of women aged ≥65 years had suffered an injury in the previous year.18 According to hospital data on injuries, this group represents 20% of ED-treated individuals,19 16% of admitted patients and 33% of deaths.20 The most common mechanisms were falls and pedestrians involved in traffic crash collisions.20 Other studies, focused on specific injuries and their trends, have shown a significant increase in the incidence of traumatic brain injury,21 and stabilisation of the incidence of hip fracture.22 The aim of this study was to describe the incidence of injuries in hospital inpatients aged >64 years in Spain according to sex, age, and the severity and mechanism of injury, and to analyse trends in incidence during the period 2000–2010 using data from the National Hospital Discharge Register (HDR).
Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://injuryprevention.bmj.com/ on November 9, 2014 - Published by group.bmj.com
Original article METHODS Design and population We performed a descriptive trends study of the population over 64 years of age resident in Spain during the period 2000–2010.
Sources of information We used data from two sources, the National HDR of the Spanish Health Information Institute (Ministerio de Sanidad, Servicios Sociales e Igualdad), which provides information on hospital discharges for injuries and data from the National Statistics Institute, which provides information on the resident population. The HDR includes information from the public hospitals network and some private hospitals, and has population coverage of over 95%. This population coverage has been steady during all the study period.
Study variables and inclusion criteria The dependent variable was the number of hospital discharges with a primary diagnosis of injury. We define injury as traumatic injury23: codes 800–904, 910–957 and 959 International Classification of Diseases Clinical Modification, Review 9. As a way of approximating the selection of new disease cases (incidence) we also excluded programmed admissions and readmissions (the HDR considers as readmission any new application for admission to the same hospital within 30 days of the patient’s prior discharge). Non-Spanish residents were excluded in order to compute national incidence rates. The independent variable was discharge year, and the stratification variables were age (in five groups: 65–69 years, 70–74 years, 75–79 years, 80–84 years or ≥85 years), sex, injury severity and injury mechanism. Injury severity was determined using the New ISS (NISS)24 computed as the sum of the three AIS most severe regardless of the region of the body in which they occur. The NISS was derived using the ICD Programs for Injury Categorization (ICDPIC) option for STATA,25 and was classified as slight or moderate (NISS
